The electronic range of motion apparatus of this invention is adapted for use as or with an elbow, knee, wrist or ankle and relates to orthoses, prostheses and continuous passive motion (CPM) machines.
With regard to orthotic elbow devices, non-powered mechanical systems, of a ratchet-lock joint design are the most common. In such design, a spring-loaded pawl, for example, engages a tooth of the ratchet wheel when the joint is flexed. The pawl is released by flexing the joint to its maximum or by a shoulder or finger controlled cable.
Another common elbow orthosis is a "dorsal elbow flexor orthosis". This orthosis is used in cases where an elbow must be stabilized orthotically at a desired degree of flexion-extension, with the ability to adjust the flexion-extension setting as the patient progresses through rehabilitation. It is non-electronic and only serves to stabilize the elbow at the desired degree of flexion-extension. The orthosis is not designed or intended to provide articulated motion as does this invention. The degree of flexion-extension of the "dorsal elbow flexer orthosis" typically is attained by rotating a screw turnbuckle assembly.
Other orthotic devices include powered elbow orthotic devices, which typically incorporate a CO.sub.2 piston and cylinder actuator. Such devices are cumbersome and require the wearing of a shoulder harness to hold the elbow control mechanism in place.
It is an object of this invention to provide an electronic range of motion apparatus for an elbow orthosis which does not require application of a harness and may fit under a patient's shirt sleeve.
With regard to prostheses, the Utah Arm.TM. is representative of a state-of-the-art prosthetic elbow. Such prosthesis is an electronic battery powered above-elbow prosthesis that is myoelectrically controlled. Position locking of the elbow assembly is accomplished via a sliding member located in the elbow molding, which engages an aluminum circumferential locking ring which is insert-molded into the forearm structure. The circumferential locking ring contains detent holes which allow the arm to be locked in 21 positions.
The elbow component is operated by a dc motor that drives a gear train/clutch system, which rotates an output shaft into two positions 180 degrees apart. The output shaft is connected to a spring, such that in each of its two rotational positions, the locking member is spring-biased to be in the locked or unlocked position.
Prosthetic elbows typically are either passive, body-powered, cable controlled, or myoelectrically controlled. Prosthetic devices including the Utah Arm.TM. are non-processor controlled, either myoelectrically or mechanically operated, and offer between 8 and 21 fixed locking positions.
It is an object of this invention to provide a processor controlled apparatus for orthotics and prosthetics.
It is another object of this invention to provide an electronic range of motion apparatus having a screw-jack type actuator that is infinitely variable and locking in approximately 200 positions in the normal range of 140 degrees of travel from full-extension to full-flexion.
It is another object of this invention to provide an electronic range of motion apparatus having a user-programmable microcontroller enabling programming of stop positions by the user.
It is another object of this invention to provide a wireless remote control system enabling convenient operation and control by the user. Previously locking flexion-extension positions could not be altered or changed by the patient.
Continuous Passive Motion (CPM) machines are powered therapy devices that move a patient's affected joint (elbow, knee, shoulder, or other) through a controlled range of motion. Simply stated, a CPM machine is a therapy machine that is used for gentle muscle stretching, or following surgery to rehabilitate the joint. Prior CPM machines have been large and cumbersome.
It is an object of this invention to provide a portable CPM machine for use outside the hospital or rehabilitation center providing flexion and extension for a joint or a human limb by controlled articulation of the affected joints and muscles.